If the top players competing at the Abu Dhabi WTA Women's Tennis Open are primarily doing so to sharpen up for next month's Australian Open, then the tournament is doing its job so far. On Thursday, the five highest-ranked players in the field – all legitimate contenders for the season's first Grand Slam – got their new campaigns under way with straight-sets wins. For some, there was understandable ring rust having not slugged it out on a tennis court since October. For others, the knockout blows came easier. If Wednesday's opening day had the feel of a preliminary card, then Thursday was the main event and top of the bill was No 1 seed Sofia Kenin. Indeed, if the American world No 4 was a prizefighter then her CV would have few KOs and plenty of unanimous points wins, using her superior skills, craft, and fitness to break down opponents. It was in that vein she opened her account for the year on Centre Court at the Zayed Sports City International Tennis Centre, defeating Chinese qualifier Zhaoxuan Yang 7-6, 6-2. In blustery conditions in the capital, Kenin, 22, hardly blew her opponent away, although 11 aces and 41 winners are encouraging statistics. Crucially, though, she is up and running for the season as she looks to build momentum towards her Australian Open title defence next month. "There were a few nerves and I had to try and find my groove," Kenin said. "Conditions weren’t easy, it was quite windy. The first set was quite tough for me – I couldn’t find the ball – but second set I started strong. "It’s down to the lack of matches, but overall I’m happy with the way I played. Obviously I need to improve my game if I want to do well here." Kenin, who faces Belgium's Kirsten Flipkens in the second round, was not the only seeded player who needed to grind for her win. Fourth seed Aryna Sabalenka – one of the WTA Tour's biggest power punchers – found herself up against the ropes in her contest with Slovenia's Polona Hercog but managed to also find a way to a 7-6, 6-2 win. Although the same scoreline as Kenin's victory, the match played out in quite different circumstances. Sabalenka, 22, entered the match on a nine-match winning run from the end of last season and after the early going, it looked as though her streak would come to an abrupt end. She trailed 5-2 in the first set and had to save five set points before taking it to a tie-break. After scrapping her way to a first-set lead, the Belarusian had an easier time of it in the second, and while it wasn't a vintage performance, as every great fighter knows, heart is just as important as skill. "I'm really happy that in these conditions I was able to find a way to win this match," said Sabalenka, who faces Australia's Ajla Tomljanovic next. "I was just focused on putting as many balls in play as I could because I didn’t have my serve, forehand or backhand [working] – I just had my character and I was trying to use it as much as I could to keep fighting for every point." For two other WTA Tour knockout artists, their first round assignments were comparatively straightforward. Sixth seed Elena Rybakina needed just an hour to dominate Italian qualifier Lucrezia Stefanini 6-1, 6-3, while third seed Karolina Pliskova faced a bit more resistance from lucky loser Despina Papamichail to win 6-2, 7-6. The Czech's win may read the same as Kenin's and Sabalenka's in reverse but she was rarely troubled and always in control against the world No 278. "It was my first match [of the season] so I didn't expect too much from myself ... I just wanted to play the best I could today," Pliskova, 28, said. "I had some good moments, some bad moments, but I'm happy to win." Of the top-seeded players in Abu Dhabi, Garbine Muguruza was handed arguably the toughest draw in former world No 10 Kristina Mladenovic - a player capable of beating anyone on her day. However, the Spanish fifth seed recovered from going down in the early rounds to have her arm raised in victory 6-2, 6-4. In the final match on Centre Court, second seed Elina Svitolina joined her fellow title contenders in the second round with a 6-4, 6-3 win over American Jessica Pegula.